Submerged flame burner



April 22, 1952 w 1N 2,594,234

SUBMERGED FLAME BURNER Filed Aug. 18, 1947 3 Sheets-Sheet-l INVENTOB ATTORNEYS Filed Aug. 18, 1947 3 Sheets-Sheet 2 r 1 1 r r z 1 I. r r I i z r .7 A I r r r I f 1 r I r f r/ z r INVENTOR ATTORNEYS N. SWINDIN SUBMERGED FLAME BURNER April 22, 1952 3 Sheets-Sheet 3 Filed Aug. 18, 1947 INVENTOR WM ATTORNEYS Patented Apr. 22, 1952 SUBMERGED FLAME BURNER,

Norman Swindin, London, England Application August 18, 1947, Serial No. 769,293 In Great Britain August 19, 1946 13 Claims.

This invention relates to improvements in submerged flame burners and has for its object the achievement of an effective burner for the purpose of concentrating liquids, and especially corrosive liquids such as solutions of sulphuric or hydrochloric acid or a mixture of both, or the spent liquors of acid pickling baths used in the manufacture of raw iron and steel goods.

The present invention has the further objective of using as fuel heavy thick oil residues, such as are unsuited for jet atomization and especially those which constitute sludges from.the acid refinement of mineral oil with which sulphuric acid is often admixed.

The use of such fuel has two advantages, firstly its calorific value is very high, and secondly the sulphuric acid residual in the oil is capable of recovery in acid concentration plants. Moreover, these sludges are substantially waste products, and their cost therefore economic.

The invention consists in an improved submerged flame burner adapted for the combus tion of heavy fuel oils, oil sludges and the like wherein the said heavy oil is admitted under pressure to an annular passage surrounding a vertical rotary shaft, said shaft terminatingin a distributing device constituted by a disc or cup fast therewith, said disc receiving said oil and under centrifugal force distributing the oil as a radially projected and atomised spray about an annular orifice constituting an admission port for air,

means being provided for igniting the combustible mixture produced.

Further according to the invention the disposition of the rotary oil fuel spraying device is accurately positioned in the head of the burner to ensure exact register of the atomized oil spray with the circular air port, Whilst the air supply is pre-heated by passing under pressure through annular passages, the innermost surface walls.

whereof constitute the boundaries of the combustion chamber. To obtain a rapid heat, exchange between the walls of the combustion chamber and the annular air passages, and to create turbulence, expanded metal strip, wire coils or equivalent air permeable metallic heat transfer means are welded or otherwise secured to the outer side wall of the combustion chamber.

With this form of burner the degree of submergence depends upon the relation between the diameter of the burner nozzle or nozzles or flame orifices and the diameter of the combustion chamber; thus large diameter nozzles require heat from the flame or hot combustion gases.

greater submergence to utilise all the effective Thus a burner body of large diameter is best provided with a series of burnernozzles of relatively small diameter.

According to a further feature of the invention and where the burners are of large dimensions, the combustion chamber is not submerged, but is fitted with a perforate base, each perforation carrying a nozzle or flame tube, that in operation is wholly immersed in the body of liquid to be heated, the horizontal component of area of the said nozzles being less than the like area of the combustion chamber.

In order that the invention shall be more fully understood reference is made to the accompanying drawings wherein:

Fig. l is a part sectional vertical elevation of the burner,

Fig. 2 shows a modified form of rotary oil dis: tributing disc.

Fig.3 shows a form of burner similar to that in Fig. 1 but in which the air is supplied direct to the combustion chamber without pre-heating..

Fig. 4 shows a form of construction of the burner in which the combustion chamber will, in operation, not be submerged, but has a dependent flame tube which will be wholly submerged in the liquid to be heated, and

Fig. 5 shows an alternative arrangement rotary oil distributing disc.

In the description and the drawings like references are used to designate like parts in the different forms of construction of the invention.

Referring to the drawings and to Fig. l the burner comprises threemain parts, the heavy oil distrib uto r head A, 2. turned cover locating plate B, and a burner body part C. The locating plate Bis formed with a machined aperture at V so as to fit accurately with a turned neck flange f the on oil distributor head A and a machine cut shoulder 3 fitting the neck ring 4 of the cover locating plate B. A shaft driven at high speed by a pulley 6 or other convenient means is mounted in a journal 1, the latter being secured toa flanged vertical sleeve 8. Interposed betweenthe abutting flanges of the journal 1 and sleeve 8 is a flanged tube 9 spaced away from the inner wall of the flanged sleeve 8 so as to provide an annular passage or annulus 9a which communicates with the oil inlet port l0.

The shaft 5 is fitted at its lowermost point with anoil distributing device in the form shown in Fig. 1 as a cup ll, said cup being coned upward centrally as at 12 and flared-upwardly and out- 3 cosity or other physical factor of the oil used. In Fig. 2 an alternative form is shown as a slightly cupped disc I la which is better suited for residual oils or oil sludges. In this form the coned shaped necking i2 is preserved but the upper face of disc I la is substantially flat or inclines upward at a slight angle. The upper surface of this type of disc may have radial or curved grooves (not shown) out in its surface.

The neck flange 2 on part A is provided with an outwardly flared skirt wall or annular portion 14, the edge of which is machined to give a definite area to the hot air orifice port it formed be- I tween the said wall [4 of the head A and machined edge of flange H, the latter forming part of the inner cylindrical wall l8 of the burner C, this wall l8 constituting part of the combustion chamber [9 and preferably being lined with a thin refractory lining such is zirconium oxide applied as a paste with silicious binder.

The burner body C is formed from three parts. the inner shell I8, an outer shell 2! and an intermediate sleeve 22. All these parts have flanges at their upper parts and are coupled together with the cover plate B by bolts 23, as shown.

The inner shell It of burner C contacts the, base plate 24, the latter being integral'with the outer shell 2|. The intermediate sleeve 22 is curtailed in length as shown and provides in its position two annular air passages, the outer passage 25 being in communication with the compressed air pipe 26, and the inner passage 21 being in communication with the hot air manifold 29 and ori fice port. 16. The outer side wall of the combustion chamber is provided with a layer of expanded metal 28 which is welded to said wall. said mesh contacting the inner face of the intermediate sleeve 22. The burner base 24 is perforate and provided with exit nozzles or apertures 30 which being below the burner immersion level, cause the inflamed gases or heated gases of combustion to penetrate deeply into the liquid treated. One or more ignition devices 3| of a known character are provided for th initial ignition of the gases. Once inflammation starts, burning is continuous. For initial starting kerosene or petrol may be used.

The operation of this form of the invention is as follows:

The heavy liquid fuel employed is put under a slight pressure and under valve control enters, the fuel inlet port It and flows down the annulus 9a and descends upon the rotating disc I l. The disc I l is rotating distributes the fuel in an atomised condition towards the hot air inlet orifice l6, 1

whereby gasification and inflammation take place within the combustion chamber l9. The inflamed admixture creates a slight back pressure owing to the flame and gas nozzles 30 having collectively a lesser area than the cross sectional area of the combustion chamber, but such back pressure is less than the pressure onthe oil and air supplies, and causes an increase in velocity of the gases through the nozzles 30.

The compressed air enters the air inlet 26 and traverses the outer annular passage 25, then ascends the inner annular passage 21 and collects heat throughout its passage, finally emerging into the combustion chamber l9 through the hot air orifice port 16.

After the initial start heat conduction to the oil passages 9a provides a relatively hot oil feed which is presented to an atmosphere of preheated air. This promotes admixture and facilitates combustion. Filters or grit separators, not shown,

may be employed in circuit with the raw oil feed, but since the oil supply to the burner is through an annular jet, the risk of choking is small. The burner is formed with a flanged necking. 32 for insertion in the top plate of an open or closed liquor tank.

With some kinds of fuel, or Where a more readily combustible fuel is employed for starting and warming up the burner according to the invention, it is found to be unnecessary to heat the air entering by the pipe 28 before admixture with the fuel spray, and in such cases the simplified form of construction shown in Fig. 3 be employed. In this embodiment of the invention, the oil distributor head A is mounted on the cover locating plate B having a neck ring ist in which fits the shoulder 3 on the distributor head, and the burner body 0' has an inturned flange Ha which forms between it and the edge [5 of the skirt M of the distributor head an orifice port lfia for the passage of air directly from the air. inlet, I26 through an air manifold its to the combustion chamber H9. The construc tion of this form of the burner is otherwise similar to that shown in Fig. 1 but the annular heating passages 25, 21 around the combustion chamber H9 are dispensed with, the'body part C of the burner consisting of the outer shell lfil and the refractory lining I 2 0.

The operation of this form of the invention is similar to that already described, but the heat generated within the combustion chamber H9 is relied on to effect eificient combustion of the inflammable mixture of oil and air. V

A further form of construction according to the invention is shown in Fig. 4, this form being more particularly suited for installations of large dimensions. In this embodiment of the invention, the cover locating plate B has aneck ring tb in which the shoulder 3 of the distributor head A fits, and an inturned flange l lb is formed on a shell 33' and provides between it and theedge it of the skirt M of the distributor head a'passage I612 for the flow of pre-heated air through an air manifold 2%. In this case the combustion chamber 219 will, in the operation of the burner, be

' supported above the level of the liquid to be heatedby flanges 39 at the lower end of the outer shell 22! which rest on the top it! of the tank 4 l. The air entering by the pipe 22G is pro-heated by passing through the annular space 33a provided betweentha concentric shells 33, at of rt fractory material within the outer shell 22 i. This annular space 33cv is filled with chequer work 35 S0 as'to provide a greater heat exchange surface. The combustion chamber 2 I9 i continuous with a flame tube 36 enclosed by an outer shell 22%, which flame tube, in the use of the invention will be wholly dependent within the body of liquid to be heated. V

The operation of this form of the invention is similar to that shown in Fig. 1.

Fig. 5 shows a different method of arranging the rotary oil distributing disc Ilb. The disc llb is inverted and arranged at the end of a hollow rotary shaft 31 through which the oil is fed, for example through perforations 31a formed in the shaft 31 adjacent the oil inlet Ii], the shaft 31 in this case being an accurate fit within the distributor head A.

Any of the burners may be fitted with a perforate shroud 38, as shown in Fig. 4, in order to assist in. the heating, agitation and circulation of the liquid in which the burner operates.

I I claim:

1. A submergedflame burner-for heating a liquid by combustion of heavy fuel oils and like fuels, comprising a combustion chamber having means for mounting it in upright position and having an opening in its lower end to communicate with the liquid to be heated, a distributor head mounted on the upper portion of the combustion chamber and having a sleeveextending downwardly and opening into the combustion chamber and having an annular portion extending downwardly and surrounding said sleeve, a shaft extending downwardly through the distributor head and said sleeve and into the combustion chamber and providing an annular passage between the shaft and said sleeve, means for supplying fuel to said annular passage, a fuel distributing disc fixed to the lower end of the shaft below said sleeve to receive fuel from said annular passage, means connected to said. shaft for rotating the disc at a sufficiently high speed to project fuel centrifugally from its periphery, an annular flange extending inwardly from the upper portion of the combustion chamber concentrically around and into proximity to the lower edge of said annular portion of the distributor head and the periphery of the disc and forming an air chamber having an annular orifice which is directed downwardly past the periphery of the disc and toward the combustion chamber, and means for supplying compressed air to said air chamber for discharging therefrom through said orifice air to admix with the fuel projected from the disc and to form therewith a combustible mixture for burning in the combustion chamber.

2. A submerged flame burner for the combustion of heavy fuel oils and like fuels, comprising, in combination, a combustion chamber having an open lower end, a sleeve and surrounding annular portion dependent within and opening into the upper portion of said combustion chamber,

said sleeve being closed at its upper end, a shaft extending through said sleeve into said combustion chamber, said shaft and sleeve providing an annular passage between them, means on the upper end of said shaft for driving said shaft, a cup-shaped disc connected to the lower end of said shaft to be driven thereby, means for introducing liquid fuel into said annular passage for delivery to said disc, an annular flange extending inwardly from the upper portion of said combustion chamber and terminating in close proximity to said annular portion and said disc to form an annular chamber with an annular orifice therein, means for introducing air under pressure to said annular chamber, and ignition means for igniting a mixture of fuel and air in said combustion chamber, said disc being formed so as on rotation thereof to project a spray of fuel therefrom under centrifugal force, and said annular orifice being disposed so as to eifect admixture of air with said fuel spray to form a combustible mixture therewith.

3. A submerged flame burner as defined in claim 2, wherein said inwardly extending flange on the combustion chamber and adjacent annular portion align said annular orifice for the flow of compressed air downwardly past and in a direction transverse to the trajectory of the fuel projected from the disc.

4. A submerged flame burner as defined in claim 2, wherein said annular orifice is formed as an annular gap disposed about the periphery of said disc to mix air from said orifice with liquid fuel projected from the periphery of the disc-and direct such mixture of fuel and air within the combustion chamber.

5. A submerged flame burner as defined in claim 2, wherein said annular chamberis formed in a distributor head closing the top of the combustion chamber, and said annular orifice is disposed at the junction of said distributor head and combustion chamber and leads from the bottom of said annular chamber and extends around and is disposed adjacent to the peripheral edge of said disc. 1 t

6. A submerged flame burner as defined in claim 2, including a cover locating plate interposed between said sleeve and combustion chamber, and wherein said annular flange extending inwardly from the upper portion of the combustion chamber and said annular portion in proximity thereto determine the width of said annular orifice.

, 7. A submerged flame burner for the combustion of heavy fuel oils and like fuels, comprising, in combination, a combustion chamber having an open lower end, a sleeve dependent within and opening into the upper portion of said com bustion chamber and having a surrounding annular portion, said sleeve being closed at its upper end, a shaft extending through said sleeve into said combustion chamber, said shaft and sleeve being arranged to provide an annular passage therebetween, power means on the upper end of said shaft for driving said shaft, a cupshaped disc fixed to the lower end of said shaft to be driven thereby, means for introducing liquid fuel into said annular passage for delivery to said disc, an annular flange extending inwardly from the upper portion of said combustion chamber and terminating in close proximity to said annular portion and said disc so as to form an annular chamber with an annular orifice therein, means for introducing air under pressure to said annular chamber, ignition means for igniting a mixture of fuel and air in said combustion chamber, and means for preheating the fuel and air by heat exchange with portions of said combustion chamber and annular portion prior to admixture in said combustion chamber, said disc being formed so as on rotation thereof to project a spray of fuel therefrom under centrifugal force, and said annular orifice being disposed so as to effect admixture of air with said fuel spray to form a combustible mixture therewith.

8. A submerged flame burner as defined in claim 7, including at least one annular passage disposed concentrically about the combustion chamber to conduct air to said annular chamber, and heat transfer means in said passage past which air flows to said annular chamber to preheat said air.

9. A submerged flame burner as defined in claim '7, including means for supporting the burner with its combustion chamber submerged in the liquid to be heated, and including concentric annular air passages disposed about the combustion chamber and connected for intercommunication at their lower ends, the inner of said passages being connected at its upper end to said annular chamber for supplying air thereto, and expanded metal sheet meshing disposed in said inner passage and welded at one side to the boundary wall of the combustion chamber.

10. A submerged flame burner as defined in claim 7, including annular passages disposed concentrically about the combustion chamber and connected to provide labyrinth flow of air to the combustion chamber, and air permeable'meshing in -one of said annular passages welded on one side to a wall of the combustion chamber and adapted at its other side to contact a wall between said passages.

11. A submerged flame burner as defined in claim 7, including an annular passage disposed concentrically about the combustion chamber and connected to said annular chamber for the flow of air thereto, and checker work arranged in said annular passage for heat transfer from the combustion chamber to air flowing through said annular passage.

12. A submerged flame burner as defined in claim 7, including means for supporting the combustion chamber above the level of liquid to be heated, and wherein said combustion chamber has a downward continuation forming a flame tube adapted to be wholly submerged in said 20 liquid.

13. A submerged flame burner as defined in 8 claim '7, including a perforated shroud surrounding the open lower end of the combustion chamber for assisting in the circulation and heating of the liquid in which the burner is submerged.

NORMAN SWINDIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 7 Number Name Date 7 1,604,955 Baker Nov. 2, 1926 1,730,440 Smith Oct. 8, 1929 1,996,336 Junkers Apr. 2, 1935 2,117,781 Wilson May 17, 1938 FOREIGN v PATENTS Number Country Date Great Britain of 1908 

